This invention pertains to an earth auger and, more particularly, to an auger having a flight with a plurality of earth-penetrating teeth spirally positioned thereon.
Various earth augers have been designed for drilling holes through strata of various materials. Past designs have used spiral flights for earth penetration. Some devices have added cutting teeth which were said to enhance drilling.
One disadvantage with such augers is that the tooth configuration, the teeth spacing and their surface drag all have a negative effect on the efficiency of the drilling process. Past auger designs have allowed for soil build up between the teeth which can diminish, if not cease, the drilling action. Also, the teeth of previous augers simultaneously engaged the ground in the same plane which presents an inefficient scraping action, undesirable drag and instability, all which further diminish the drilling action. Moreover, past teeth were not relatively positioned so as to provide a pneumatic drill-type action on the earth during the drilling process.
Accordingly, it is desirable to present an effective auger which avoids these past problems so as to enhance the drilling process.
In response thereto I have invented a novel auger design. My auger design includes an axial shaft/shank having a spiral cutting flight wound therearound. The flight begins adjacent the initial penetration point of the shank and spirally winds about the shaft towards the opposed end of the shank. The initial portion of the cutting flight presents a plurality of conical cutting teeth which are spirally displaced from the shank to provide a succession of single earth penetrating cuts, i.e., each tooth engages the underlying surface prior to engagement of an upstream tooth. The teeth are radially and longitudinally spaced relative to the shank such that an imaginary line extending through the teeth defines a spiral cutting edge which cooperates with the subsequent upstream cutting edge of the spiral flight. Thus, a corkscrew drilling effect is presented. The teeth are positioned, relative to each other and a horizontal plane normally passing through the axial shank, such that a pneumatic drill type action is directed onto the earth while preventing earth buildup between the teeth. Such relationships present a discrete stair-stepped pattern of earth removal with the pneumatic effect of the teeth first weakening the tiered earth and then fracturing each tier for effective removal. Each subsequent tooth cuts an earth relief for the housing of the preceding teeth so as to preclude drag of the preceding teeth housing on the earth. The plurality of teeth extend 360° about the shaft which further enhances the drilling action.
Accordingly, it is a general object of the invention to provide an improved earth auger.
Another object of this invention is to provide an auger, as aforesaid, having an earth cutting spiral flight wound therearound with a plurality of earth penetrating teeth forming a portion of the spiral flight.
A further object of this invention is to provide an auger, as aforesaid, wherein the teeth are easily replaceable within their respective housings.
Another object of this invention is to provide an auger, as aforesaid, wherein the teeth extend at least 360° about an axial shank.
A further object of this invention is to present an auger, as aforesaid, wherein the teeth are radially spaced, relative to an imaginary central axis of the shank, so as to preclude earth build up between the teeth during the drilling action.
Another object of this invention is to provide an auger, as aforesaid, wherein the teeth are vertically spaced so as to provide a single cut, corkscrew drilling action.
A still further object of this invention is to provide an auger, as aforesaid, wherein the teeth are spirally, vertically and radially spaced so as to provide discrete stair-step tiers for earth removal during the drilling action.
Another object of this invention is to provide an auger, as aforesaid, wherein the teeth are positioned, relative to the earth, such that a pneumatic drill-type or chatter action is provided against the underlying earth.
Another object of this invention is to provide an auger, as aforesaid, wherein the aforesaid pneumatic and corkscrew actions enhance the drilling process.
A still further particular object of this invention is to provide an auger, as aforesaid, wherein the spiral flight presents a spiral cutting edge first presented by the plurality of teeth, as aforesaid, and then a spiral cutting edge.
Another particular object of this invention is to provide an auger, as aforesaid, wherein the auger design stabilizes the auger during the drilling action to preclude undesirable auger movement.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, a now preferred embodiment of my invention.